1. Field of the Invention
The present invention relates to a skin irritation alleviation agent (i.e., "alleviator") and a composition containing the same. More specifically, the present invention relates to a skin external application composition or a cosmetic or similar composition containing a polyoxyalkylene-modified organopolysiloxane, as an alleviator, having a low skin irritation effect and an extremely high safety factor when used on the human body.
2. Description of the Related Art
A surfactant is indispensable as, for example, a solubilizing agent, emulsifier or dispersing agent for dissolving, for example, perfume components in an aqueous system, homogeneously mixing oil components and aqueous components, or dispersing pigments into water or oil components. However, surfactants generally cause a strong skin irritation effect. Accordingly, the surfactant formulated in cosmetics is generally used in a minimum necessary amount.
Surfactants are used in various compositions and products. For example, a tacky tape or sheet for skin external use (e.g., a tacky tape or sheet for patch tests, a tacky tape or sheet for medical or submedical use) has been widely used for medical purposes, but since it is adhered to the skin for a long time, it is well known to cause a skin irritation effect, namely, sticking plaster eruption.
Sticking plaster eruption is now widely known as a contact dermatitis, and the cause for skin irritation thereof is considered to be greatly dependent on the adhesive force of the tape or sheet or the components of the tape or sheet, and on the influences of the stabilizer or accelerator for emulsion polymerization monomers. Moreover, that from the stabilizer of the colloid for storage, and the like cannot be disregarded.
False eyelashes have been widely used in order to make the eyelashes appear longer and denser and add an attractiveness to the eyes. To adhere a false eyelash to the eyelid, an adhesive adopted for false eyelashes has been employed, and from the viewpoint of use characteristics such as adhesive force and ease of removal, a natural or synthetic latex or a synthetic emulsion has been used as the adhesive component.
However, to retain a false eyelash for a long time, the adhesive force must be fairly strong, and for this reason, partly because of the use of the eyelid, which is sensitive, a problem arises in that skin irritation may occur if a person has a sensitive skin, and the like.
A further example is a decolorant usually comprises a first agent having one or two or more alkali agents selected from alkanolamines such as monoethanolamine, diethanolamine, triethanolamine and the like, ammonia, sodium hydroxide, potassium hydroxide, formulated optionally further together with ammonium salts, sodium salts, potassium salts with acids such as carbonic acid, bicarbonic acid, phosphoric acid, citric acid, nitric acid, hydrochloric acid and the like, as the main component, and a second agent comprising an oxidizing agent (generally hydrogen peroxide) as the main component. During use, the first agent and second agent are mixed and applied by a brush onto head hair or unnecessary hair to be decolored on arms or legs, left to stand for about 10 to 30 minutes, and then washed away. The mixing ratio of the first agent and the second agent may be an approximate ratio depending on the purpose, but the ratio generally employed is the first agent:the second agent =1:1 to 1:5.
Also, to obtain a sufficient decoloration power, the alkali agent is adjusted during mixing of the first agent and the second agent so that the pH is generally 9 to 12, and hydrogen peroxide is formulated to an amount of 1 to 5% by weight during mixing. Further, during coating of the hair or unnecessary hair on arms or legs, to enable an easy coating or to prevent dripping of the liquid, the liquid must be appropriately viscous, and therefore, is in a gel-like or cream-like form. For this purpose, a surfactant is used. A surfactant has the actions of a gelling agent, emulsifying agent or dispersing agent, and solubilizing agent, but generally causes the problem of skin irritation. The above respective irritations are augumented synergetically when a decolorant containing an alkali and hydrogen peroxide having a strong skin irritation effect is formulated with a surfactant, whereby rubor, eruption or even sometimes edema may occur, with pain to the user, thus posing a serious problem for the health and appearance of the skin.
Yet another example is that of depilatories in the form of a wax, cream, liquid or tacky tape are generally utilized. However, most of these depilatories have dermatological safety problems, different from conventional external dermatological preparations. For example, in the case of a depilatory wax, the wax is generally heated to a temperature higher than the melting point to make it liquid, then the skin to be depilated is coated with the melted wax, and upon solidification, the solidified wax is peeled off together with the hair. Thus, this is a depilatory utilizing a physical action, and the base used therefor is rosin (pine resin), which is primarily composed of abietic acids, which cause irritation considered to be due to the impurities contained therein, whereby the coated skin sometimes is covered with red swellings or blisters. Also, a depilatory cream or depilatory liquid comprises an S--S bond cleaving agent for the keratin structure of hair formulated in a liquid base, for which a thioglycolic acid is generally used. However, many of the S--S bond cleaving agents have serious skin irritation effects and skin safety problems. Similarly, in the case of a tacky tape or sheet, skin eruptions will frequently occur, which may be considered to be caused by the components in the tacky layer.
Another example is an eyeliner used to make the eyes more impressive and attractive. An eyeliner is frequently formulated with a synthetic resin emulsion capable of forming an oil-resistant, water resistant film, for cosmetic preservation, to prevent a makeup breakdown by skin fat or foundation or the oil or fat contained in an eyeshadow, or a makeup breakdown caused by sweat or tears. However, to maintain the cosmetic effect for a long period, the film formed must be relatively firm, and thus, partly because of the very sensitive tissue at the edge of the eye, a problem arises in that skin irritation may occur if a person has sensitive skin and the like.